Sunday, January 22, 2012

Nearly half of AP vulnerable to floods

Andhra Pradesh witnesses severe cyclones almost every two to three years. About 44 per cent of the State is vulnerable to tropical storms and related hazards. The coastal belt is said to be the most vulnerable region in India to these natural phenomena.

Cyclones on the east coast originate in the Bay of Bengal, the Andaman Sea or the South China Sea, and usually reach the coastline of Tamil Nadu, Andhra Pradesh, Orissa and West Bengal, which are the most vulnerable to these types of hazards. Two of the deadliest cyclones of this century, with fatalities of about 10,000 people in each case, took place in Orissa and Andhra Pradesh during October 1971 and November 1977 respectively. The super cyclone of Orissa in 1999 caused large-scale damage to life and property.

Along the Andhra coast, the section between Nizampatnam and Machilipatnam is the most prone to storm surges and the loss of human and property caused by cyclones around the Bay is very high. Once the cyclones enter the mainland, they give way to heavy rains which often translate into floods. This season is no exception. Heavy rains coupled with inflows from Karnataka induced floods causing some damage to crops in Mahbubnagar, Adilabad, Prakasam district, Vijayawada, Krishna and Guntur.

Many drought-prone areas adjacent to coastal districts in eastern maritime states are thus vulnerable to flash floods originated by the torrential rains induced by the cyclonic depression. In addition to cyclones and its related hazards, monsoon depressions over the north and central areas of the Bay of Bengal move until reaching north and central India, including parts of Andhra Pradesh, bringing heavy to very heavy rains and causing floods in the inland rivers between June and September.

In Andhra traditionally, the flood problem has been confined to the flooding of smaller rivers. But the drainage problem in the coastal delta zones has worsened, multiplying the destructive potential of cyclones and increasing flood hazards. A critical factor is maintenance of irrigation systems. On several occasions, deaths were caused by breaches in tanks and canals as well as over-flooding caused by silting and growth of weeds.
Effect of repeated disasters
The regular occurrence of disasters both natural and man-made in Coastal region has had a series of repercussions on the State’s economy, its development policies and political equilibrium and daily life of millions of people. The coastal region suffers repeated cyclones and floods.

The 1977 cyclone and tidal wave, which resulted in great loss of life, attracted the attention of the Central and State Governments and the international donor communities, as did those of 1979, 1990 and 1996. The floods in the Godavari and Krishna Rivers caused havoc in the East and West Godavari and Krishna districts.

Along the coastline, the section between Nizampatnam and Machilipatnam is the most prone to storm surges. The fertile delta areas of the Godavari and the Krishna rivers, which contribute substantially to the State's economic prosperity, face flood and drainage problems, and more so in the aftermath of cyclones.
More than sixty cyclones hit AP this century.

The incidence of cyclones seems to have increased in the past decades, to the extent that severe cyclones have become a common event occurring every two to three years, repeatedly and severely affecting the state's economy.

May cyclones are relatively rare in the region, and only about 13 affected AP in this century. However, when they badly hit the delta areas, as it happened in 1979 in the Krishna district - where 80 per cent of the casualties occurred - the population may be in higher danger than usual. May is the rice harvesting season, and a good number of itinerant laborers come to the delta from less fertile areas of AP in search of work.

Since they lack awareness of the area's most prevalent hazards, this migrant population is more vulnerable than the permanent delta residents. Traditionally, the flood problem in AP had been confined to the spilling of smaller rivers and the submersion of marginal areas.

However, the drainage problem in delta zones of the coastal districts has worsened, thereby multiplying the destructive potential of cyclones and increasing flood hazards.

Moreover, when a storm surge develops, as it was the case during the November 1977, May 1990 and November 1996 cyclones, threats to humans and property multiply as the sea water inundates coastal areas which are already being subjected to torrential rains.

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